TPO27

　　Inthis listening material, the professor states several points about global cooling caused by the Little Ice Age.

　　First,the reading material states that after the ocean currents melted, the glaciersproduce an enormous number of cold freshwater into the Gulf Stream. This actioninfluenced the earth’s climate strongly, while the professor in the listening material disagrees that the cooling water just affected Europe and parts ofNorth America, but it can’t explain global cooling, or the cooling in southernarea.

　　Second,the reading material says that the volcanic eruption caused the Little Ice Ageas they generate dark clouds with dust and sulfur gas into our atmosphere whichwill reduce the earth’s temperature. By contrast, the professor contradictsthat the volcanic eruption produce colorful clouds and gases, but those gasesare not strong enough to decrease the earth’s temperature.

　　Lastly,the reading material mentions that the decrease of human population affect theearth’s temperature indirectly because we no longer cut substantial number oftrees and let the forest grow freely, these trees absorb carbon dioxide andthat will reduce the earth’s temperature. However, the professor objects thatpeople still cut a large number of trees and the short cease of deforestationis not long enough to cause the global cooling.